Since the invention of integrated circuits, the semiconductor industry has experienced continuous rapid growth due to constant improvements in the integration density of various electronic components and semiconductor packages. For the most part, these improvements in integration density have come from repeated reductions in minimum feature size, allowing more components to be integrated into a semiconductor chip or package.
One approach for allowing more components to be integrated into a semiconductor structure is the adoption of three dimensional integrated circuit (3D IC) stacking techniques, in which silicon wafers and/or dies are stacked on one another. A common technique for stacking a semiconductor wafer and a substrate (e.g., glass or sapphire) employs the use of adhesive materials. However, one drawback of such technique is that the additional adhesive material increases the total thickness of the semiconductor stack and also deteriorates the quality of signal transmission within the semiconductor stack. Therefore, what is needed is a semiconductor stack without adhesive material for bonding different layers of wafers or dies.